Cook and stir sausage in medium skillet over medium heat 5 minutes, or until lightly browned. Remove from heat. Stir in beans; set aside.
Mix yogurt, mustard and syrup in small bowl until well blended; set aside.
Divide spinach among 4 dinner plates; top evenly with the sausage mixture, mango and onions. Drizzle with the yogurt mixture just before serving.